The largest electric grid operator in the United States declared an emergency alert for a second day amid high temperatures across the East Coast and Midwest.
On Friday, PJM Interconnection LLC, which serves 13 states, declared another Energy Emergency Alert Level 1 until the end of Friday. Excessive heat advisories and warnings cover a number of areas across those states—from Illinois to New Jersey.
“Dangerous heat peaks in the Northeast, Mid-Atlantic, and Midwest today and Saturday before a cold front provides these regions with a welcomed return of cooler and more comfortable temperatures Sunday,” said the NWS on its website. “Excessive heat continues in the Southwest U.S. through Saturday before a new heat wave builds across the South and Gulf Coast early next week, and persists through the week.”
A day before, the grid operator issued a similar level-one emergency due to heat. It said that its preliminary peak load was around 148,000 megawatts and is forecast to peak at around 155,000 megawatts on Friday evening.
“PJM has issued these alerts to help prepare generators for the onset of intense heat,” the operator also said, referring to gas-powered generators. “A Hot Weather Alert helps to prepare transmission and generation personnel and facilities for extreme heat and/or humidity that may cause capacity problems on the grid. Temperatures are expected to be near or above 90 degrees in these regions, which drives up the demand for electricity,” it added.
On Thursday, utility spokesman Jeffrey Shields told The Associated Press that PJM “currently has enough generation to meet forecast demand, but operators continue to monitor the grid conditions for any changes.”
The Midcontinent Independent System Operator, which mostly covers states in the Midwest and Northern Plains, issued a similar alert on Thursday.
Heat Advisories
Some 200 million people in the United States, or about 60 percent of the U.S. population, are under a heat advisory or flood warning or watch and have been since Thursday, according to the NWS.Night temperatures are forecast to stay hotter than usual, prompting excessive heat warnings from the Plains to the East Coast. From Thursday to Friday, the number of people under a heat advisory rose from 180 to 184 million and the number of people under a flood warning or watch dropped from 17 to 10 million.
Moisture moving into the Southwest has cooled the southernmost counties of California and parts of southern Arizona some, but excessive heat warnings remain for much of the region.
On top of the heat, severe thunderstorms are forecast for parts of the Great Lakes and Ohio Valley, west to the Middle Missouri Valley through Saturday morning.
U.S. cities that are currently under heat warnings include Virginia Beach, Washington, Philadelphia, St. Louis, and Kansas City, the NWS said Friday.
“These areas may see high temperatures climb well north of 90F, even 100F in some areas,” it said. “In addition, oppressive humidity currently affecting much of the country will contribute to widespread heat indices of 100-110+ over these areas.”
“Nighttime temperatures may only fall into the upper 70s and low 80s, which will reduce overnight relief from the daytime heat. Many places are set to break their temperature records for daytime highs as well as warm nighttime lows through Saturday morning. If you are affected by this heat wave, it is imperative to practice heat safety, especially if spending extended periods of time outdoors.”
In New York City, utility Con Edison sent out a text blast asking residents to be frugal with air conditioning to conserve electricity. Overtaxing an electrical grid can mean blackouts, which are not just an inconvenience, but can lead to equipment failures and major pollution as equipment restarts.
The Biden administration on Thursday also directed the Labor Department to increase inspections of potentially dangerous workplaces such as farms and construction sites and called for heightened enforcement of heat safety violations.
